A PHASE UNWRAPPING TECHNIQUE FOR OBJECT RELIEF DETERMINATION

Phase shifting methods are widely used in photomechanics to analyse fringe patterns obtained from interferometry, moire, etc. The phase is determined by modulo 2pi and an unwrapping process is needed. An algorithm is presented which avoids most of the inconsistency of the phase field. It can be applied to the relief determination of virtually any object shape. In this paper, two applications are performed using the projection of a parallel line grating with a pitch equal to 4mm. The accuracy is shown to be around 0.1 mm.